Ole Gunnar Solskjaer has confirmed Victor Lindelof suffered an injury which forced him off at half-time during the 5-2 win over Bournemouth.
The Swedish defender was replaced at the break by teammate Eric Bailly with United 3-1 up at that stage.
Lindelof showed no signs of any problems during the first half, but Solskjaer revealed after the match he had picked up an injury.
Solskjaer told BT Sport: "He [Lindelof] struggled with his back but hopefully won't be too bad."
United are next in action on Thursday, giving the 25-year-old at least some time to try and recover for the trip to Aston Villa.
Bailly had only been on the field in Lindelof's absence for two minutes when he conceded a penalty for a handball.
United looked shaky at the back all afternoon, even prior to Lindelof's departure, and had fallen behind to Junior Stanislas' opener.
The Cherries' forward nutmegged Harry Maguire inside the box before firing inside David de Gea's near post from an acute angle after just 16 minutes.
Goals from Mason Greenwood, Marcus Rashford and Anthony Martial gave United a solid two-goal cushion to take into the second half, before Josh King reduced the deficit from the penalty spot following Bailly's adjudged misdemeanour.
Greenwood added his second shortly after to restore the two-goal advantage, with Bruno Fernandes completing the scoring with a free-kick from the edge of the box five minutes later.
Despite the injury to his centre-half, Solskjaer was positively upbeat after the victory, which stretches United's unbeaten run to 16 matches in all competitions.
"Very, very happy with today - with the energy in the team and the goals we scored," Solskjaer said. "I think that was a game for the fans. That is definitely one the Stretford End would have enjoyed."
Adding of his impressive front line, Solskjaer said: "They are on the same team and working towards one common goal. That is one of the positive things about the forwards they are good friends and keep challenging each other."
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